July 2023
SUMMARY OF THE METEOROLOGICAL READINGS AT DURHAM UNIVERSITY OBSERVATORY
July 2023
Temperatures (all temperatures in degrees Celsuis; all averages 1991-2020)
Mean daily maximum: 19.6 Difference from average: -0.6
Mean daily minimum: 11.8 Difference from average: +0.5
Mean air temperature: 15.7 Difference from average: -0.1
Absolute maximum: 27.8 (8th)
Absolute minimum: 8.9 (4th)
Mean grass minimum: 10.5 Difference from average: +1.0
Absolute grass minimum: 6.6 (20th)
Mean concrete minimum: 11.8
Absolute concrete minimum: 8.3 (4th)
Number of ground frosts: 0 Difference from average: 0
Number of air frosts: 0 Difference from average: 0
Mean soil temperature at 300 mm depth: 17.1
Mean soil temperature at 1000 mm depth: 15.7
Rainfall (all totals in millimetres; all averages 1991-2020)
Total for the month: 113.6 Difference from average: +51.6
Percentage of the average: 183%
Wettest day: 17.6 (22nd)
Number of rain days (>0.1 mm): 24 Difference from average: +9
Number of wet days (=>1.0 mm): 16
3-month total rainfall to 31st July 2023: 191.8 Difference from average: +24.1
6-month total rainfall to 31st July 2023: 314.2 Difference from average: +8.7
12-month total rainfall to 31st July 2023: 716.6 Difference from average: +35.6
Sunshine (all totals in hours; all averages 1991-2020)
Total for the month: 148.9 Difference from average: -26.3
Percentage of the average: 85%
Mean daily sunshine: 5.0 Difference from average: -0.7
Sunniest day: 7.2 (7th)
Number of days with no recorded sunshine: 0
Note that the monthly sunshine total is now calculated from the UKMO E&NE regional total. Daily sunshine totals quoted here and in the data summary are uncorrected.
Wind (kph; all data from the West Building roof, Lower Mountjoy campus)
Average wind speed: 2.7
Maximum gust: 61.2 (1st, 12:30, W)
Comments on July 2023
This was the first month with below-average mean air temperature this year. Nights were warmer than average, but days were disappointingly cool, with only 2 days above 25 C° (which is the average number for the month, but nevertheless a disappointing total). The weather was doubly disappointing given how hot the previous two Julys have been. It was the 13th wettest July since 1850, with 24 rain days. As expected, sunshine was below average, but not excessively so, the 50th dullest July since 1882.
Emeritus Professor Tim Burt
Department of Geography
Durham University